A monitoring integrated circuit (hereinafter referred to as “monitoring IC”) for monitoring an assembled battery is in operation through receiving the power supply from the battery cell which is an object to be monitored by itself. Accordingly, if there is a fault occurred in the battery cell, the monitoring IC does not operate and hence loses the monitoring function. In order to solve the difficulty mentioned above, the invention described in, for example, Patent Literature 1 provides a power source separately from the battery cell used as the power source for the monitoring IC so as to enhance the reliability.
However, even when the configuration disclosed in the Patent Literature 1 is used, there is no any change in consuming the energy of the battery cell when the monitoring IC receives the power supply from the battery cell. In particular, in a case of carrying out a monitoring operation, the monitoring IC carries out communication with a microcomputer as the host control device to receive a control command and send the detected data. Accordingly, it raises a difficulty in increasing the voltage variation of the battery cell with larger current consumption and hence the ability of the assembled battery cannot be used effectively.
[Patent Literature 1] JP-2011-163847-A